Materials Literature
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We report a study of the isotropic–nematic (I–N) transition in fluids of molecules interacting through the hard Gaussian overlap (HGO) model. This model is computationally simple and shears some similarities with the widely used hard ellipsoid (HE) fluid. The I–N coexistence properties of HGO fluids have been accurate…
Erbium doped Al2O3 films with concentrations up to 6×1020 Er cm−3 have been prepared in a single step process by pulsed-laser deposition. Alternate ablation of Al2O3 and Er targets has been used to control the in-depth distribution and in-plane concentration of Er3+ ions independently. The characteristic Er3+ photolum…
The solution structure of DsrC, an archaeal homologue of the gamma subunit of dissimilatory sulfite reductase, has been determined by NMR spectroscopy. This 12.7-kDa protein from the hyperthermophilic archaeon Pyrobaculum aerophilum adopts a novel fold consisting of an orthogonal helical bundle with a beta hairpin alo…
Abstract The syntheses and characterization of linear silarylene‐siloxane‐diacetylene polymers 3a–c and their thermal conversion to crosslinked elastomeric materials 4a–c are discussed. Inclusion of the diacetylene unit required synthesis of an appropriate monomeric species. 1,4‐Bis(dimethylaminodimethylsilyl)butadiyn…
By using laser ablation on mixtures of transition metal cobalt and group-14 elements, binary alloy cluster anions were produced while no binary alloy cluster cations were detected, and the homocluster cations of group-14 elements appeared at very low abundance. The differences between clustering abilities of germanium…
The dynamic behavior of a holographic grating induced in a homeotropically aligned dye-doped liquid-crystal film is investigated. In the presence of an applied dc voltage, photoexcited azo dyes induce a photorefractive grating and then diffuse and are adsorbed onto cell substrates. The reorientation of liquid crystals…
Layered structures of cubic yttria-stabilized zirconia (YSZ) sandwiched between two layers of platinum/YSZ composites with the platinum concentration varying between 20 and 55 vol % were prepared. Large double-layer capacitances were obtained due to the presence of large three-dimensional electrode surface areas in th…
In earlier attempts to shift the substrate specificity of glutamate dehydrogenase (GDH) in favour of monocarboxylic amino-acid substrates, the active-site residues K89 and S380 were replaced by leucine and valine, respectively, which occupy corresponding positions in leucine dehydrogenase. In the GDH framework, howeve…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTA Nonisocyanate Route to Monodisperse Branched PolyurethanesAndrew J. Clark, Juan Echenique, David M. Haddleton, Thomas A. Straw, and Paul C. TaylorView Author Information Department of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K. [email protected]Cite this: J. Org…
Abstract The engineered design and manufacturing of high‐quality fabrics have been targets of textile technology in this century; however, this has not yet been achieved. There are two reasons for this. One is that a method for the objective evaluation of the primary performance of fabric as clothing material was not…
Time-resolved vapor diffusion into low modulating porous silicon dielectric mirrors has uncovered salient information about the spatial concentration distribution of the vapor within the porous matrix. Results indicate that relatively high concentrations of vapor result in instantaneous capillary condensation in the p…
Magnetic entropy change (ΔS) of a single crystal Ni50.1Mn20.7Ga29.6 alloy under different applied fields has been investigated near the martensitic–austenitic structural transition temperature of 219 K. With increasing applied field from 0.2 to 5 T, the sign of ΔS changes from positive to negative. At 0.8 T the positi…
The compound Cs10.5[(V16O40)(Si4.5V1.5O10)].3.5H2O is the first example of an extended structure in which a polyoxometallate anion is linked by an extended tetrahedral unit.
A real-space method is developed to calculate molecular hyperpolarizabilities in the time-dependent density functional theory. The method is based on the response function formalism which was developed by Senatore and Subbaswamy for the third harmonic generation of rare-gas atoms [Phys. Rev. A 35, 2440 (1987)]. The re…
Transmission electron microscopy and high resolution x-ray diffraction are used to characterize defects in ZnO layers grown by plasma-assisted molecular-beam epitaxy on (0001) sapphire. Two- and three-dimensional types of growth modes are described and the observed mosaic structure is analyzed in each case. It is foun…
Mesoporous silica materials have been synthesised in strongly acidic media at pH = 1.3 using high concentrations of a non-ionic surfactant (Brij 76) as a structure-directing agent. Well-defined ordered mesoporous silicas with hexagonal (HI), lamellar (L∞) and solid phase (S) structure have been prepared at room temper…
Single crystals have been grown in the (Bi1/2Na1/2)1−xBaxZryTi1−yO3 perovskite system by a self-flux method over the range of compositions y=0.04 and x=0.06–0.012. Rhombohedral (x⩽0.08) and tetragonal phase (x⩾0.09) crystals have been obtained that do not show polarization or field-induced strain hysteresis characteri…
A photoluminescence (PL) band, the M band, was observed in photoluminescence spectra for various excitation densities in high-quality ZnO epitaxial thin films. The M band intensity increased superlinearly with an increase in the excitation intensity, suggesting that the observed PL band is due to a biexciton state. In…
A convergent synthesis employing porphyrin building blocks has afforded dendrimeric multiporphyrin arrays containing n Zn-porphyrins (n = 4, 8, or 20) and one free base- (Fb-) porphyrin joined via diarylethyne linkers. Size exclusion chromatography was used extensively for purification. The arrays have sufficient solu…
Abstract In this article, we review the progress made in the area of industrial twisted fibrous structures. First, we focus on the general geometrical description of the structures, and then move to issues including the tensile behavior and fracture process. The effects of fiber bending and torsion, strain rate, and v…